Question

Using the thermodynamic information in the ALEKS Data tab, calculate the standard reaction free energy of the following chemical reaction: 4PCI, (g) → P,()+6C1, (g) Round your answer to zero decimal places.

please explain step by step. I'm really confused.

Answer 1

Standard free energy of reaction can be calculated using standard free energy formation
of reactants and products taken from thermodynamic table

dGrxn = sum of free energy formation of Products - sum of free energy formation of reactants

4PCl3(g) --> P4(g) + 6Cl2(g)

dGf(PCL3) =-267.8 kj/mol

dGf(P4) = 24.0 kj/mol

dGf(Cl2) = 0 kj/mol

these numbers taken from standard thermodynamic table

dGrxn = 1[24.0 kj/mol] + 6*[0 kj/mol] - 4*[-267.8 kj/mol] = 1095 .2 KJ
  
after rounding

dGrxn = 1095 KJ
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:)